Caroline K. Lee

De novo 9q gain in an infant with tetralogy of Fallot with absent pulmonary valve: Patient report and review of congenital heart disease in 9q duplication syndrome.

Genomic disruptions, altered epigenetic mechanisms, and environmental factors contribute to the heterogeneity of congenital heart defects (CHD). In recent years, chromosomal microarray analysis (CMA) has led to the identification of numerous copy number variations (CNV) in patients with CHD. Genes disrupted by and within these CNVs thus represent excellent candidate genes for CHD. Microduplications of 9q (9q+) have been described in patients with CHD, however, the critical gene locus remains undetermined. Here we discuss an infant with tetralogy of Fallot with absent pulmonary valve, fetal hydrops, and a 3.76 Mb de novo contiguous gain of 9q34.2‐q34.3 detected by CMA, and confirmed by karyotype and FISH studies. This duplicated interval disrupted RXRA (retinoid X receptor alpha; OMIM #180245) at intron 1. We also review CHD findings among previously reported patients with 9q (9q+) duplication syndrome. This is the first report implicating RXRA in CHD with 9q duplication, providing additional data in understanding the genetic etiology of tetralogy of Fallot, CHD, and disorders linked to 9q microduplication syndrome. This report also highlights the significance of CMA in the clinical diagnosis and genetic counseling of patients and families with complex CHD.

Prenatal Counseling of Fetal Congenital Heart Disease

Opinion statementThe field of fetal cardiology has advanced greatly over the last two decades and congenital heart defects can now be identified in utero with a high level of accuracy. Prenatal counseling of parents given the news of a fetal cardiac defect is an important role of the fetal cardiologist. Prenatal counseling is a complex task that requires skill to perform and interpret fetal echocardiograms, an understanding of fetal and postnatal cardiovascular physiology, knowledge of therapeutic and surgical options, and of long-term outcomes including quality of life. Just as important is the manner in which the information is conveyed and the support offered to the parents as these affect parental understanding, influence decision-making, and may impact the parents’ emotional and psychological coping.

Autoimmunity Against the Heart and Cardiac Myosin in Children With Myocarditis.

BACKGROUND Host autoimmune activity in myocarditis has been proposed to play a role in development of cardiac disease, but evidence of autoimmunity and relationship to outcomes have not been evaluated in pediatric myocarditis. METHODS We performed a multi-institutional study of children with clinical myocarditis. Newly diagnosed patients were followed for up to 12 months and previously diagnosed patients at a single follow-up for serum levels of autoantibodies to human cardiac myosin, beta-adrenergic receptors 1 and 2, muscarinic-2 receptors, and antibody-mediated protein kinase A (PKA) activation in heart cells in culture. Results were compared with those of healthy control children. RESULTS Both previously diagnosed patient at follow-up (P = .0061) and newly diagnosed patients at presentation (P = .0127) had elevated cardiac myosin antibodies compared with control subjects. Antibody levels were not associated with recovery status at follow-up in either group. PKA activation was higher at presentation in the newly diagnosed patients who did not recovery normal function (P = .042). CONCLUSIONS Children with myocarditis have evidence of autoantibodies against human cardiac myosin at diagnosis and follow-up compared with control subjects. Differences in antibody-mediated cell signaling may contribute to differences in patient outcomes, as suggested by elevated antibody-mediated PKA activation in heart cells by the serum from nonrecovered patients.

Reproducibility of Left Ventricular Dimension Versus Area Versus Volume Measurements in Pediatric Patients With Dilated CardiomyopathyCLINICAL PERSPECTIVE

Background— Multiple echocardiographic methods are used to measure left ventricular size and function. Clinical management is based on individual evaluations and longitudinal trends. The Pediatric Heart Network VVV study (Ventricular Volume Variability) in pediatric patients with dilated cardiomyopathy has reported reproducibility of several of these measures, and how disease state and number of beats impact their reproducibility. In this study, we investigated the impact of observer and sonographer variation on reproducibility of dimension, area, and volume methods to determine the best method for both individual and sequential evaluations. Methods and Results— In 8 centers, echocardiograms were obtained on 169 patients prospectively. During the same visit, 2 different sonographers acquired the same imaging protocol on each patient. Each acquisition was analyzed by 2 different observers; first observer analyzed the first acquisition twice. Intraobserver, interobserver, interacquisition, and interobserver-acquisition (different observers and different acquisition) reproducibility were assessed on measurements of left ventricular end-diastolic dimension, area, and volume. Left ventricular shortening fraction, ejection fraction, mass, and fractional area change were calculated. Percent difference was calculated as (interobservation difference/mean)×100. Interobserver reproducibility for both acquisitions was better for both volume and dimension measurements (P⩽0.002) compared with area measurements, whereas intraobserver, interacquisition (for both observers), and interobserver-acquisition reproducibilities (for both observer-acquisition sets) were best for volume measurements (P⩽0.01). Overall, interobserver-acquisition percent differences were significantly higher than interobserver and interacquisition percent differences (P<0.001). Conclusions— In pediatric patients with dilated cardiomyopathy, compared with dimension and area methods, left ventricular measurements by volume method have the best reproducibility in settings where assessment is not performed by the same personnel. Clinical Trial Registration— URL: https://www.clinicaltrials.gov. Unique identifier: NCT00123071.

Spontaneous Echocardiographic Contrast Associated with Portosystemic Shunt Due to Persistent Patent Ductus Venosus

We describe a case of an infant with a single ventricle physiology, who presented with spontaneous microbubbles originating from her inferior vena cava. Imaging revealed a persistent patent ductus venosus, leading to a portosystemic shunt, streaming the microbubbles into the heart. We discuss the possible mechanisms for this rare phenomenon in a child.